A very routine determination made countless times every day in numerous industries is the determination of the percentage of volatiles in a given substance. Such tests are run on literally thousands of items ranging from agricultural products such as tests which determine the percentage of moisture in corn, wheat, oats, tobacco and the like to textiles, foods, paints etc. Numerous industrial products are also tested to determine the percentage of volatiles, whether such volatiles be water, solvents or other diluents. These tests include the determination of the solids in paints, varnishes, lacquers, paper products and the like. Practically all items which are sold on a weight basis and are likely to absorb moisture require correction for such gain, such that a customer is not charged for water or other diluent. In the same manner, numerous items require a certain specified moisture or volatile level to be suitable for further use and are sold in the trade as being within specified rangess. Thus, considerable time is expended on quality control processes and testing to obtain the proper or desired percentage of moisture or solvent in the substance being sold.
Previously, tests for determining the percentage of volatiles was conducted by typical wet chemistry analysis. The sample to be tested would first be weighed by an operator and then placed on a hot plate or in a vacuum oven for a predetermined period of time, normally on the order of 30 minutes to 2 hours. The sample would then be cooled, reweighed and a calculation made to determine the percentage of the volatile removed from the sample.
Another method used is known as the Karl Fisher determination. This test involves a titration with a specified chemical reagent and a subsequent calculation of the amount of moisture present based on the titration.
Such methods are time consuming and require operator skill. The accuracy of the test is often directly related to the skill and care exercised by the operator. Further, while such tests are largely repetitious, an operator is substantially limited in the number of tests which can be performed in a given period. In many instances, such as in quality control work, the time required for a single test, i.e. as much as 2 hours or more, greatly inhibits plant operations such that processing conditions are normally two hours ahead of the test results. This requires advance interpretation of processing conditions and estimations as to when the product is within specifications.
It is an object of the present invention to provide an apparatus which automatically and quickly determines the amount of volatiles in a substance in a fraction of the time previously required.
It is a further object of the present invention to provide an apparatus which will prepare bone dry samples without destroying or damaging the same, which samples can be used in subsequent analytical determinations which require dried samples.
It is another object of the present invention to provide a method which eliminates the need for operator skill in determining the amount of volatiles in a substance, reduces or eliminates the chance of human error and reduces testing time to minutes or seconds per sample.
These and other objects will become apparent to those skilled in the art from the description of the invention which follows.